Holography is well known and widely used in many commercial applications including display holography, security, advertising, data storage and holographic optical elements and gratings. A holographic image is produced when reconstructing light is diffracted at a complex diffraction grating of spatially varying spatial frequency, which, in the simplest terms, re-directs the light towards the viewer in such a way as to give the illusion that the light is coming from a three-dimensional object.
Depending on the geometry of the recording system, there can be two types of holograms, i.e. transmission and reflection. The orientation of the fringes in the two types is fundamentally different as are their methods of manufacture and their effects on the reconstructing light, particularly white light. The present application is directed to reflection holograms.